Apparatus for tempering watch-springs



(No Model) 3 Sheets-Sheet 1.

P. SEDGWIGK APPARATUS FOR TEMPERING WATCH SPRINGS.

Patent ed Sgpt. 6, 1887.

Ins/en or:

Q i a PETERS. Piwmumn n (No Model.) 3 Sheets-Shee't 2.

P. SEDGWIOK. APPARATUS P0P TEMPERING WATCH SPRINGS.

No. 369,560. A Patented Sept. 6, 1887.

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3 Sheets-Sheet 3.

K O I W G D E S R (No Model.)

Patented Sept. 6, 1887.

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UNITED STATES PATENT OFFICE.

FREDERICK SEDGVICK, OF CHICAGO, ILLINOIS.

APPARATUS FOR TEMPERING WATCH-SPRINGS.

SPECIFICATION forming part of Letters Patent No. 369,560, dated September 6, 1887.

Application filed Decemher'Ql, 1886. Serial No. 222,149. (N0 model.)

To 0. whom it may concern:

Beit known that I, FREDERICK SEDGwIcK, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvements in Apparatus for Tempering VVatch-Springs, of which the following is a description, reference being had to the accompanying drawings, forming a part of this specification, in which Figure 1 is a side View of said apparatus. Fig. 2 is a like view of a portion of the same, showing the heating-tube and a part of the cooling-chamber in longitudinal section. Fig. 3 is a plan view of the device for taking up the slack of the heated strip. Fig. 4. is aside view of the cooling-chamber, a portion being broken away to show the interior. Fig. 5 is a plan view of a portion of the end ofsaid chamber from which the metal strip is drawn, together with the clamping device and guiderods upon which the same is" mounted. Fig. 6 is a side view,in detail,ofthe clamp for drawing the metal strip through the temperingchambers. Fig. 7 is a side view of a portion of said apparatus, showing a modification of the construction in which the heating-tube is dispensed with; and Fig. 8 is a like view showing a further modification of said construction.

Like letters of reference indicate like parts in the different figures.

The object of my invention is to provide an apparatus for tempering metal wires andstri ps, and particularly watch-mainsprings, whereby they may be heated and tempered in long lengths or strips, preferably while protected from the deteriorating action of the atmosphere, the heating thereof being accomplished by means of an electric current.

Further objects are to provide means for taking up the slack of the strip when expanded by heat, to prevent the warping and buckling of the metal while in the cooling-bath, and to provide means for clamping the metal strip and drawing it step by step through the tempering-chambers, all of which is hereinafter more particularly described, and definitely pointed out in the claims.

A in the drawings represents a table or frame, to which are rigidly attached standards or supports a a a a. Upon the supports a a is mounted a tube, B, preferably of glass, one

end of which is inserted within a plug, 1), which is in turn inserted within a cap, 0, attached by means of a screw-thread to one end of a metal tube, 0, which is provided with a similar metal cap, a, at the opposite end. The caps 0 o and the plug b are provided with central openings or holes, b 0 either round or oblong, as may be required, for the reception of the metal strip D, which is drawn through said tubes, respectively, and attached to reels E E at the opposite ends of the apparatus. I prefer to make the plug 1) somewhat shorter than the cavity which it enters, thereby leaving a small chamber, F, Fig. 2, in said cap, which is preferably filled with mercury, for the purpose hereinafter stated. A tube or opening,f, Figs. 2 and 4, is provided for this purpose. At the end of the tube B where the metal strip enters I prefer to insert a packing of asbestus, B, or other similar insulating or non-conducting material, so that the action of the electric current upon that portion of the strip within the tube may not be varied or affected thereby, while at the same time said packing may serve to prevent the admission of air to the tube B.

After passing the wire or metal strip D through the tubes B and C the latter is filled with metallic shot, sand, particles of metal or other loose material G, but preferably shot, which rubs or wipes against the metal strip D upon all sides, and prevents any but a longitudinal movement thereof as well as the formation of bubbles thereon. A reservoir, H, Fig. 1, is placed above the tube C, and connected therewith by means of a pipe, h. A drip-pipe,j, is also provided below the tube, and by preference at the opposite end, below which may be placed a drip-cup, J. The reservoir H is supplied with oil, water, or other liquid from which the tube C may be charged, the flow thereto and therefrom being regulated by means of stop-cocks hj.

Between the tube B and reel E, I place a stationary block or support, K, to which is firmly secured a cleat, Z, having horizontal guiderods Z Z rigidly attached thereto for the guidance of a loose cross-head, Z connected upon one side by a plate, Z", to a spring-clamp, L, and upon the opposite side to a stationary block, 1*, in the rear by means of a spiral spring, Z which serves to normally hold the ICO eross-head Z" against the block Z, the compres sion of the clamp L upon the strip D being great enough to expand the spring Z and permit the cross-head to be drawn forward when the strip is passed through the tubes. This causes that portion of the strip which is in the tubes to be constantly under tension. The clamp L is wide enough so that the underjaw may be slotted to permit the strip D to pass through beneath the same and back to the reel, as shown in Fig. 2.

Bindingposts m m are attached to the plate Z and to the end of the tube O,'as shown, from which wires M M connect directly with the respective poles of a source of electricity-as a dynamo or electric battery, but preferably the former. Aswitch or circuit-breaker, h Figs. 1 and 4, is interposed in the circuit. It will thus be seen that the metal strip D completes the electric circuit between the clamp L and the mercury in the chamber F.

Extending horizontally from the cap 0 of the tube 0 are guide-rods a a, supported by posts a a at the ends. Mounted loosely upon said rods is a slide or cross-head, N, adapted to be reciprocated upon said rods. Spiral springs or at the respective ends of said rods act as cushions for said cross-head in its backward and forward movement.

. The cross-head N is bored longitudinally, to permit the strip D to pass loosely through it, while a slot, at, Fig. 6, is cut out from beneath, into which is pivoted at a an elbow-lever, O, the long arm of which projects downwardly, while the short arm 0 is adjusted to clamp against the strip D when the lever is moved in one direction, while it releases said strip when reversed, the pressure of the belt, hereinafter described, upon the long arm serving to return the cross-head to its original position.

A bracket, 1), is rigidly attached to the bottom of theframe A, within which are mounted pulley-wheels P P of different diameters, but rigidly attached to each other. One end of a belt, 12, is attached to the wheel P, while the other is secured to a spiral spring, 19 which is in turn secured to the frame A, and is normally under tension. A belt, q, is trained around the pulley P in an opposite direction from that of the beltp over a pulley, q, when it is attached to a foot-lever, Q, the loose end of which is normally raised. A third belt, R, is trained around a pulley at the side of and rigid with the pulley P and over smaller pulleys, r 1", attached to the table A. Aslot ted link, 0*, is interposed in said belt, which engages the depending arm of the lever 0, so that the latter, and with it the cross-head N, may be reciprocated, as stated, by the action of the belt, the arm 0 at the same time clamping the strip D and carrying it in the direction of the arrow and then releasing it, while the cross-head is carried back to repeat the operation. By means of the spring 1) the link 1" is normally retained in the position shown in Figs. 1 and 6, which causes the cross-head N to rest against the springs 02?, thus preventing the arm 0 from clamping the strip D so long as the treadle is not depressed. Upon depressing the treadle Q until the tension of the spring 19 is overcome the pulleys P are revolved and the belt and lever O are actuated in the direction of the arrow. This causes the end of the short arm 0 to press or clamp the metal strip against the upper side of the pars sage through the slide N, and the latter, moving with the lever and belt, carries the strip with it, and thus draws alength from the tube B into the tube C. At the same time the reel E, which is mounted upon a shaft, 6, which is continuously revolved by the belt 0, Fig. 1, revolves and winds thereon the portion of the strip D which has been drawn forward by the clamp, said reel being loosely mounted-upon said shaft, but having a frictional bearing thereon, which, however, is of such a degree that the reel remains stationary, except when the strip is drawn toward it; but the tendency to revolve is sufficient to retain the strip D under constant and uniform tension.

Fig. 7 shows a modification of said construction, in which the heating-tube B is dispensed with. \Vith a comparatively strong current, so that the strip may be suddenly heated, the oxidation is not nearly so great as that produced under the old methods, in which it requires a much longer time to heat the metal to the proper degree, and with the use ofthe shot or loose particles Gr in the chamber 0, the oxidized film is wholly or in part removed from the strip when it emerges from said chamber; but I prefer to protect the strip from the action of the atmosphere while being heated, as the original cold-rolled film of the metal may thereby be preserved in its entirety, thus producing greater resiliency and toughness in the finished spring. A further advantage arising from the protection of the strip, as described, arises from the fact that, being surrounded by heat and radiation prevented, a weaker electric current may be employed.

Fig. 8 shows a means for protecting the metal strip fromatmospheric influence, which may be employed in lieu of the tube and with equally good results. It consists of two plates or strips, 13 B, of asbestus or mica, between which the metal strip is drawn, and which is both a non-conductor of heat and electricity, and hence cannot affect the action of the electric current upon the metal strip.

The operation of said apparatus is as follows: Assuming the strip D to have been passed through the tubes, as described, and attached to the reels, and the tube 0 to have been f lled with oil and shot or other rubbing or wiping medium, the electric current is turned onto that portion of the strip D within the electric circuit until said strip is heated to redness, which may be readily seen through the glass; or, if asbestus plates or a metal tube is used, a specified time may be allowed for the heating. As soon as heated, the strip is considerably expanded, but the slack is taken up by means of the spring Z acting upon the clamp L, as well as the tendency of the reel E to revolve. Thus vthe strip is kept straight within the tube or protecting-envelope, and is evenly heated. As soon as it is brought to a red heat, as stated, the treadle Q is depressed, which serves to transfer the heated portion to the cooling-bath 0. As it is drawn into the oil between the shot, all air-bubbles which tend to form thereon and cause the spring to warp are immediately displaced, and an even uniform temper is imparted to the metal, thereby saving the further operation of reheating the spring, which is commonly resorted to for the purpose of straightening it.

The air may be exhausted from the chamber B, if preferred, or said chamber may be filled with any substance or gas which will protect the metal from oxidation; but neither is necessary, as, after one or two lengths of metal have been heated within the chamber, the oxygen becomes exhausted, and the surface of the metal is not thereafter affected by the atmospheric constituents remaining. I therefore regard one method as the practical equivalent of the other.

Very good results may be obtained when a heating-tube is used by dispensing with the asbestus packing in the end of the tube, as the heat from the spring expands the atmosphere therein and tends to expel rather than admit fresh air; and, while I do not confine myself to such construction, I prefer to close the end of the tube, as stated, the packing used being of any suitable insulating material which enables a metal tube to be used, if preferred. Instead of placing the mercury in the cavity F, I have found that equally good results may be obtained from putting a considerable quantity into the tube 0, when it amalgamates with the shot and forms a satisfactory electric contact or connection between the metal strip D and the tube 0.

I am aware that it is old to harden or harden and temper metal wires and stripsin continuous lengths by first heating the same by means of furnaces, gas-jets, molten lead, prussiate of potash, or electricity, either in the open air or while protected therefrom by means of mufflers or tubes, and then passing the same into a cooling medium. I do not, therefore, claim any of these features, broadly; nor do I confine myself to any specific method of heating the wire, as it is well known that either method specified may be employed with good results and without varying the principle of my invention; but as I have 'found electric heating to be more uniform and satisfactory, I prefer to adopt and have therefore described that method. In whatever manner, however, the metal strip is heated it is important and essential that means should be provided to prevent the same from buckling or warping when drawn into the cooling-bath, as it is well known that a great portion of the expense in the manufacture of watch-springs arises from the difficulty experienced in straightening the spring after it is tempered, and the treatment to which it is necessary to submit it for this purpose tends to greatly injure its quality both in resiliency and uniformity. This not only takes the life out of the spring, but when once warped in hardening the strip can never again be made entirely straight. By combining loose particles of solid matter-as metallic shot, sand, or other suitable niaterialthe bubbles which otherwise form upon the heated strip when drawn into the cooling-liquid and which, being non-conductors of heat, prevent the metal from cooling evenly, are dispelled or wiped off, and thus the strip is evenly hardened without the formation of crooks-or kinks therein. This I regard,therefore,as the prominent feature of novelt-yin my invention,

and it is obvious that it would produce the same result in whatever manner the strip were heated or however it might be drawn through the receptacle containing the cooling and wiping medium, whether continuously or in sections.

I am further aware that spring-clamps and analogous devices have been used to produce a uniform tension while the heated strip is being drawn through the tube continuously; but I am not aware that any means has been heretofore provided for governing the tension and taking up the slack within the tube where the strip is drawn forward step by step. Th s is an important feature where that method is adopted, in that as soon as the strip becomes heated it expands and becomes so bent that portions touch against the sides of the tube, which results in imparting an uneven temper to the strip when hardened. My improved device fully overcomes this objection.

What I claim, therefore, and desire to secure by Letters Patent, is-

1. In an apparatus for tempering metal wires and strips, the combination,with means for heating said strips, of a suitable receptacle containing oil, water, or other cooling medium,together with a wiping material consisting of loose particles of solid matter, and means for drawing the heated portion of said strip into and from said receptacle, substantially as and for the purposes'iset forth.

2. In an apparatus for hardening or tempering metal strips, the combination of means for heating the strip with areceptacle containing oil, water, or other cooling medium, together with a wiping material consisting of loose particles of solid matter, whereby bubbles are prevented from forming on the metal strip while the same is being cooled and hardened, substantially as described.

3. An apparatus for tempering metal wires and strips, consisting of a source of electricity, means for placing the metal strip into circuit with the electric current, achamber containing a cooling and wiping medium, through which the metal strip is passed, and means for drawing the heated portion of the strip into and from said chamber, substantially as and for the purposes set forth.

4. An apparatus for tempering metal wires and strips, consisting of two tubes or chambers through which the metal strip is passed, a source ofelectricity, and electrical connections with that portion of the metal strip incloscd within the first tube or envelope, means for taking up the slack of the metal strip when expanded by heat, and means for transferring said heated portion to the secondary tube or chamberstep by step,substantially as specified.

5 In an apparatus for tempering metal strips, the combination of means for heating the strip by exposing it to the action of the electric current, with a chamber filled with a cooling and wiping medium, and means, as a treadle and automatic clamping device, for drawing said strip into and from said chamber in successive lengths or sections as fast as heated and tempered, substantially as described.

6 In an apparatus for tempering metal strips, the combination of means for. heating the strlp by exposing it to the action of the electric current, with a receptacle containing 011 or other cooling medium, together with shot or other loose particles of solid matter and mercury for preventing the formation of bubbles upon the metal strip and for providmg' a more perfect electric contact therewith, and means for passing said strip through said receptacle, substantially as specified.

'7. In an apparatus for tempering metal strips, the combination of a source of electricity, means for placing the metal strip into circuit with the electric current, means for protecting said portion from the oxidizing action of the atmosphere, a spring-clamp for maintaining the portion to be heated under resilient tension and taking up the slack thereof when expanded by heat, and a chamber con taining a cooling medium and a suitable filling ofloose solid matter to wipe or rub the strip and prevent the formation of bubbles thereon, together with a sliding clamp and means for connecting the same with a foot-lever for drawing said strip,section by section,into and from the coolingchamber, substantially as set forth.

8. In an apparatus for tempering metal wires and strips, the combination of an electrogenerator, means for bringing a section of the metal strip into circuit therewith, a coolingchamber, and a sliding clamp for drawing the strip through the chamber, section by section, with means, as afoot-lever and intermediate connections, for actuating the same, and suitable springs for easing or cushioning the movement of said sliding clamp, to prevent the breakage of the hardened strip, substantially as described.

FREDERICK SEDGXVICK. W'itnesses:

D. H. FLETCHER, M. M. G-RIDLEY. 

